But with Matt Comyn, the bank gets a retail banker who has witnessed first-hand the havoc that can be wreaked with scandals, cover-ups and poor whistleblower policies.

Indeed, the Austrac money laundering scandal, which had come on the back of a string of other scandals, almost cost him the top job.

It seems the CBA board settled on an insider because it gets a known quantity. With the royal commission set to kick off in the next couple of weeks, it couldn't afford to outsource the risk to an outsider.

Comyn is 42 and will be the face of a new culture that the bank desperately needs to create to rebuild trust. He has the challenge of changing an organisation that has a reputation of putting profit before people.

His first move in this area was to accept a lesser salary package than his predecessor Ian Narev.

But at the end of the day his personality will play a role in changing the culture. Comyn has a very different personality to Narev, whose abundance of confidence and background as a consultant didn't translate well with politicians and some regulators.

Comyn comes across as unassuming, polite and willing to listen, which is what the bank needs as it stares down a royal commission, legal action with Austrac, a public inquiry by the Australian Prudential Regulation Authority into its culture and most importantly, the court of public opinion.

Comyn takes up the job on April 9, a couple of weeks before the final report by APRA, which is unlikely to be pretty. Narev won't be there to cop it on the chin.

CBA's problem was never about its financial performance but its culture, which rewarded success at any cost, and allowed a string of scandals to get out of hand, hence creating a trust deficit in the community.

The handling of the scandals sent a strong message that CBA could do what it liked with little comeback.

The biggest contribution Comyn can make to CBA is stop future scandals and he is the best placed to do it. He has seen first-hand what can go wrong when they are brushed over. He was there when Storm Financial blew up and various other scandals. He saw the ramifications of not dealing with them head on.

It means he should understand the need for accountability so that if a scandal emerges, it is dealt with immediately instead of downplayed. This means sacking wrongdoers instead of promoting them or allowing them to move quietly elsewhere without impunity. It also means respecting the role of whistleblowers.

When The Age and the Sydney Morning Herald broke the CBA financial planning scandal on June 1, 2013, which involved forgery and fraud and a cover-up by management, the bank tried to diminish the issue, saying it happened in the past, it was a few bad apples and victims had been compensated.

Indeed, it didn't bother to answer most of the questions sent. Instead it released a short statement full of spin and little substance, which didn't wash well with the public, which had been horrified by the treatment of the bank's customers who had bravely told their stories. One of them was the mother-in-law of the then treasurer, Joe Hockey, which illustrated the arrogance of the bank and its lack of political savvy.

The community was also disgusted by the treatment of whistleblower Jeff Morris, a financial planner who had only wanted to do the right thing when he saw elderly people being ripped off. He ended up suffering from post traumatic stress disorder and a ruined career for speaking up. Again, a less arrogant bank that wanted to rebuild trust, would have tried to help.

When a Senate inquiry was called that recommended a royal commission in 2014, the bank issued a bland press release with quotes from the PR department rather than the then chairman or CEO. It infuriated the public and both sides of politics which believed such a damning report required a direct quote from a senior member of the bank.

It was this sort of arrogance and dismissal of the issues that landed the bank in a lot of hot water at parliamentary inquiries. It highlighted the growing disconnect between the community and that of senior executives at CBA.

Then in 2016 when the life insurance scandal hit the front pages of The Age and the SMH and ABC's Four Corners, again the bank tried to diminish the problem, apologising to a few victims but never taking ownership of the treatment of customers.

Again, nobody but the whistleblower Dr Ben Koh was punished.

By the time it got to Austrac, the trust deficit had got too big. This is why the appointment of Comyn will be so important.